Molecular specification of facial branchial motor neurons in vertebrates

Dev Biol. 2018 Apr 1;436(1):5-13. doi: 10.1016/j.ydbio.2018.01.019. Epub 2018 Jan 31.


Orofacial muscles are critical for life-sustaining behaviors, such as feeding and breathing. Centuries of work by neuroanatomists and surgeons resulted in the mapping of bulbar motor neurons in the brainstem and the course of the cranial nerves that carry their axons. Despite the sophisticated understanding of the anatomy of the region, the molecular mechanisms that dictate the development and maturation of facial motor neurons remain poorly understood. This fundamental problem has been recently revisited by physiologists with novel techniques of studying the rhythmic contraction of orofacial muscles in relationship to breathing. The molecular understanding of facial motor neuron development will not only lead to the comprehension of the neural basis of facial expression but may also unlock new avenues to generate stem cell-derived replacements. This review summarizes the current understanding of molecular programs involved in facial motor neuron generation, migration, and maturation, including neural circuit assembly.

Keywords: Embryonic patterning; Motor neuron development; Orofacial motor neurons.

Publication types

  • Review

MeSH terms

  • Animals
  • Body Patterning / genetics
  • Cell Movement / genetics
  • Facial Nerve / embryology
  • Facial Nerve / metabolism*
  • Motor Neurons / metabolism*
  • Neurogenesis / genetics*
  • Vertebrates / embryology
  • Vertebrates / metabolism